diff --git a/src/serial_posix.c b/src/serial_posix.c
index 2648294..b53177d 100644
--- a/src/serial_posix.c
+++ b/src/serial_posix.c
@@ -1,6 +1,3 @@
-#define _POSIX_C_SOURCE 199309
-#define _BSD_SOURCE 
-
 #include <stdlib.h> // malloc, free
 #include <string.h>	// strerror
 #include <errno.h>	// errno